Texture, microstructure and consumer preference of mango bars jellified with gellan gum

Abstract

Studies for the development of a novel convenient fruit product based on mango puree and gellan gum were carried out. Two gellan types (low acyl-L and high acyl-H) used in specific L/H ratios (75/25, 50/50, 25/75) for an overall concentration of 1 g of gellan/100 g of puree were tested, in order to design different mango bars. The influence of the L/H gellan ratio on their texture properties (TPA and SR tests), microstructure (Cryo-Scanning Electron Microscopy) and texture sensory acceptance (Preference-Ranking test) was studied. The results obtained enabled to separate the bars in two groups: the ones showing greater hardness and brittleness (only L gellan, and L/H at the ratios of 75/25 and 50/50); and those presenting a softer structure with higher cohesiveness and springiness values (L/H of 25/75 and only H gellan). The microstructure of mango bars was consistent with the texture results. Those presenting higher hardness have shown a microstructure composed of a denser biopolymer network with lower pore size; while for softer bars with higher springiness, larger pores and thin strings were observed. From the Preference-Ranking test, the most appreciated mango bar in terms of texture was the one prepared with a L/H ratio of 25/75.